Physics – Premed Windsor University School of Medicine and
Health Sciences
J.C. RoweCourse Instructor.
Pre Med – PhysicsChapter 0 - Intro
There is more to lectures than the power point slides!
Engage your mind - go beyond the class!
PHYICSPHYICS
What is Physics ?
• Def’d-1: analysis of nature & how the universe behaves
• Def’d-2: the scientific study of matter and energy and how they interact with each other
Involves:• motion, heat, light, electricity, magnetism,
atomic structure, gravity etc..
How Does The Natural World Function?
Fundamental Questions e.g:
•How did the universe begin?•How will the universe change in the future?•How / why does the Sun keep on shining?•What are the basic building blocks of matter?•How does matter exist?
UNITS (Systéme Internationale)Dimension SI (mks) Unit Definition
Length meters (m) Distance traveled by light in 1/(299,792,458) s
Mass kilogram (kg) Mass of a specific platinum-iridium allow cylinder kept by Intl. Bureau of Weights and Measures at Sèvres, France
Time seconds (s) 9,192,631,700 oscillations of cesium atom
Prefixes
In addition to mks units, standard prefixes can be
used, e.g., cm, mm, m, nm
Significant Figures: Division
Find the value of 6.49m divided by 5.1037sCalculator gives 1.271626467 !Too many figures. FALSE AccuracyOnly 3 significant figures. Why? 1.27m/s
Number # Significant Figures Rule(s)
48,923 5 1
3.967 4 1
900.06 5 1,2,4
0.0004 (= 4 E-4) 1 1,4
8.1000 5 1,3
501.040 6 1,2,3,4
3,000,000 (= 3 E+6) 1 1
10.0 (= 1.00 E+1) 3 1,3,4
Estimate the number of times a human heart beats during its lifetime.
Estimate - a typical heart beats ~60 times per minute:
ESTIMATION
2.4 x 109 beats/lifetime
Length:DistanceDistance Length (m)Length (m)Radius of visible universe 1 x 1026
To Andromeda Galaxy 2 x 1022
To nearest star 4 x 1016
Earth to Sun 1.5 x 1011
Radius of Earth 6.4 x 106
Sears Tower 4.5 x 102
Football field 1.0 x 102
Tall person 2 x 100
Thickness of paper 1 x 10-4
Wavelength of blue light 4 x 10-7
Diameter of hydrogen atom 1 x 10-10
Diameter of proton 1 x 10-15
Time:
IntervalInterval Time (s)Time (s)Age of universe 5 x 1017
Age of Grand Canyon 3 x 1014
32 years 1 x 109
One year 3.2 x 107
One hour 3.6 x 103
Light travel from Earth to Moon 1.3 x 100
One cycle of guitar A string 2 x 10-3
One cycle of FM radio wave 6 x 10-8
Lifetime of neutral pi meson 1 x 10-16
Lifetime of top quark 4 x 10-25
Mass:
ObjectObject Mass (kg)Mass (kg)Milky Way Galaxy 4 x 1041
Sun 2 x 1030
Earth 6 x 1024
Boeing 747 4 x 105
Car 1 x 103
Physics Student 7 x 101
Dust particle 1 x 10-9
Top quark 3 x 10-25
Proton 2 x 10-27
Electron 9 x 10-31
Neutrino 1 x 10-38
Conversion of Units• Example:
The Distance from point A to the Andromeda Nebula is 2 x 106 light years. What is the distance in km ?
1. Conversion factor: 1 ly = 9.5 x 1012 km 2. Insert conversion factor: d = 2 x 106 ly & 1 ly = 9.5 x 1012 km = 2 x 106 x 9.5 x 1012 km = 1.9 x 1019 km
Remember: 10a x10b = 10a+b
10a / 10b = 10a-b
Example:
• If the speed limit on the German autobahn is 150 kilometers/hour. What is the speed limit in metres/hour ?
• What is the speed limit in mile/ hour?
Lecture 1, Activity
A very good fastball pitcher can throw the ball 100 mi/hr. What is the ball speed in m/s? (Answer in 3 significant figures)
1 - 450 m/s2 - 44.7 m/s3 - 0.045 m/s4 – 28.1 m/s5 - 28.2 m/s
correct
Dimensional Analysis• Dimension indicates the nature of a physical quantity or the
type of unit.
Example:Dimension of distance is length : [L]Unit of distance is m , km, miles, …
Note:Dimensions of left-hand side and right-hand side of anequation have always to be the same, e.g. when you start witha quantity of dimension length you have to finish with oneof dimension length.
Powerful check of your computation !
TrigonometryDefinition of sine, cosine and tangent:
Sin = opp/hyp
Cos = adj/hyp
Tan = opp/adj
Pythagorean Theorem: c2 = a2 + b2
Physics Applied • The Lunar Dome
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